The aim of the VIRGO investigation (Variability of solar IRradiance and Gravity Oscillations) on SOHO (SOlar and Heliospheric Observatory) is to determine the characteristics of pressure and internal gravity oscillations by observing irradiance and radiance variations, to measure the solar total and spectral irradiance and to quantify their variability over periods of days to the duration of the mission. VIRGO contains two different active-cavity radiometers for monitoring the sol- ar 'constant' (DIARAD and PM06-V), two three-channel sunphotometers (SPM) for the measurement of the spectral irradiance at 402, 500, and 862 nm with a bandwidth of 5 nm, and a low-resolution imager (Luminosity Oscillation Imager, LOI) with 12 'scientific' and 4 guiding pixels, for measuring the radiance dis- tribution over the solar disk: at 500 nm. The instrumentation has been described in detail by Frohlich et al. (1995). In addition, the observed in-flight performance and operational aspects of the irradiance observations are described by Frohlich et al. (1997), and those of the LOI by Appourchaux et al. (1997).

Table of Contents:
1 The First Results from Soho.- First Results from VIRGO, the Experiment for Helloseismology and Solar Irradiance Monitoring on SOHO.- In-Flight Performance of the VIRGO Luminosity Oscillations Imager aboard SOHO.- Structure and Rotation of the Solar Interior: Initial Results from the MDI Medium-L Program.- Time-Distance Helioseismology with the MDI Instrument Initial Resulte.- First Results of the SUMER Telescope and Spectrometer on SOHO. I. Spectra and Spectroradiomefry.- First Results of the SUMER Telescope and Spectrometer on SOHO. II. Imagery and Date Management.- High-Resolution Observations of the Extreme Ultraviolet Sun.- Application of Spectroscopic Diagnostics to Early Observations with the SOHO Coronal Diagnostic Spectrometer.- Flows and Dynamics in the Corona Observed with the Coronal Diagnostic Spectrometer (CDS).- First Energetic Particle Events Observed by the ERNE Instalment.- Anomalous Cosmic-Ray Helium, Nitrogen, and oxygen in 1996. Measurements of the ERNE Instrument on-board SOHO.- 2 The First Results from Soho.- Performance and Early Results from the GOLF Instalment Flown on the SOHO Mission.- First Results on p Modes from GOLF Experiment.- First View of the Solar Core from GOLF Acoustic Modes.- In-Flight Performance of the VIRGO Solar Irradiance Instruments on SOHO.- Measurements of Frequencies of Solar Oscillations from the MDI Medium-l Program.- Tri-Phonic Helioscismology: Comparison of Solar p Modes Observed by the Helioseismology Instruments Aboard SOHO.- Modeling the Distribution of Magnetic Fluxes in Field Concentrations in a Solar Active Region.- Bursts of Explosive Events in the Solar Network.- Doppler Shifts in the Quiet-Sun Transition Region and Corona Observed with SUMER on SOHO.- Observations of Polar Plumes with the SUMER Instalment onSOHO.- Polar Plume Anatomy: Results of a Coordinated Observation.- Eruptive Prominence and Associated CME Observed with SUMER, CDS aid LASCO (SOHO).- First Observations of Coronal Hole Structure and Evolution Using SOHO-CDS.- EUV Observations of a Macrospicule: Evidence for Solar Wind Acceleration?.- EUV Blinkers: The Significance of Variations in the Extreme Ultraviolet Quiet Sun.- Active Regions Observed in Extreme Ultraviolet Light by the Coronal Diagnostic Spectrometer on SOHO.- High-Velocity Hows in an Active Region Loop System observed with the Coronal Diagnostic Spectrometer (CDS) on SOHO.- The Mg/Ne Abundance Ratio in a Recently Emerged Flux Region Observed by CDS.- The Relationship between UV and X-Ray Active Region Stuctures.- SOHO CDS-NIS in-Flight Intensity Calibration Using a Plasma Diagnostic Method.- EIT Observations of the Extreme Ultraviolet Sun.- EIT and LASCO Observations of the Initiation of a Coronal Mass Ejection.- First Results from the SOHO Ultraviolet Coronagraph Spectrometer.- Composition of Coronal Streamers from the SOHO Ultraviolet Coronagraph spectrometer.- First View of the Extended Green-Line Emission Corona at Solar Activity Minimum Using the LASCO-C1 Coronagraph on SOHO.- LASCO Observations of Disconnected Magnetic Structures out to beyond 28 Solar Radii during Coronal Mass Ejections.- The Relationship of Green-Line Transients to White-Light Coronal Mass Ejections.- MHD Interrelation of LASCO Observations of a Coronal Mass Ejection as a Disconnected Magnetic Structure.- First Results from SWAN Lyman ? Solar Wind Mapper on SOHO.- Recurrence of Energetic Particle Flux Anisotropy as ObserVed by ERNE on 9 My 1996.- Implications of Proton Anisottopy DeVelopment Observed by the ERNE Instalment During the 9 My 1996 Solar Particle Event.-CD-ROM Viewing Instructions and Contents.